WO 99/56883 A1 discloses a previously known device having a centrifugal separator with a centrifugal rotor for separating particles from a gas. The centrifugal separator is arranged to be driven by a pressure fluid which is generated by a combustion engine, wherein the centrifugal rotor is arranged with a pneumatic or hydraulic motor, for instance a turbine, which is adapted to be rotated by the pressure fluid. The drive arrangement of this known device enables, in a simple manner, both a very high rotational speed of the centrifugal rotor and that the centrifugal separator may be located at a desired place near the combustion engine. This makes the device useful for cleaning crankcase gas from a combustion engine.
WO 2011/005160 A1 discloses a further device including a centrifugal separator for cleaning crankcase gas with a centrifugal rotor which is driven by a pressure fluid via an impulse turbine. In particular the impulse turbine (shown in more detail in FIGS. 1 and 29-34) is arranged with buckets for receiving a jet of pressurized fluid from a nozzle directed against the buckets. The buckets are configured such that the fluid jet direction is reversed along a height of the bucket. This turbine has proven to be both simple and effective in driving the centrifugal rotor.
These drive arrangements are often adapted for the specific operating conditions of the centrifugal separator. One aspect is to make the drive arrangement as efficient as possible. There is a desire to keep the energy consumption of the drive arrangement at a minimum, while maintaining or even increasing the separating efficiency of the centrifugal separator.